Help with Screen Resolutions

[Methanoid]

PowerMac PCIE G5 7,3 2.3DC with flashed Radeon X1950XT running Leopard.

I cannot get it to boot when connected via DVI to my HDMI Dell 2712H monitor (1080P). The monitor complains I need to feed it a compatible source like 1920*1080 @ 60Hz. It does this AFTER displaying Apple logo and just as OSX actually loads desktop

I can get it to boot fine and display happily on a VGA connected old Dell monitor which goes to 1280*1024 from memory

I can boot with BOTH connected and I get a 1080P on the 1080P monitor and some old res on the VGA monitor. But remove the VGA and I lose my 1080P.

I've messed with the monitor settings in Prefs and it was set to 60Hz NTSC and I tried Millions of colours and Thousands.

Just want to fix it so its 1080P and I can use my G5 with my KVM switch. I wonder if it needs tweaking to 60.01Hz or 59.97Hz or some such twaddle.

Ideas/help, please?

 

[mustagcoupe]

Try resetting the pram. Start the computer and hold down CMD, OPT, P, R before it chimes. Wait for the computer to chime 3 times then let go of the keys and let it boot normally.

 

[Methanoid]

Did that and SMC and no difference. It shows Apple logo but as soon as desktop comes to load, black screen (and message about monitor frequency). If I connect a 2nd monitor (VGA via DVI connector), it loads and displays a 60Hz 1080P signal. Very frustrating. Wondering if I need to insert some EDID emulator to force monitor?

 

[weckart]

It does very much look like it is struggling with that particular monitor.